Preserving means for fish nets



1933- P. R. ANDREWS PRESERVING MEANS FOR FISH NETS Filed-Aug. 31, 1931 I Patented Feb. 14, 1933 rinnm a. mnnnws, or anemia, wasnmeron PBESEBVNG m8 FOR FISH mars Application and An a :1, mi. Serial ll'o. 560,255.

and chemical rot, the fibers of the net become.

less able to resist the force of tidal movements, currents and other submarine violence resulting in final rupture and loss of the entire structure.

But perhaps the worst condition arises from the accretlon of fungous growths, bacterial slime and the skeletons of marine organisms throughout the meshes ofthe net.

until the load becomes sufliciently great to cause complete collapse of the fabric.

Many methods have been employed with more or less success to retard chemical decay and to inhibit the accumulation of these pernicious growths. Tar has been for long used as a protective coating and poisonous salts, (usually copper sulphate), have been introduced into the fibers of the nets by immersion in aqueous solution. Such treatments, however, have not onl been costly, tedious and cumbersome, but t ey have been attended by resultant ill effects sometimes as objectionable as the troubles they essayed to remedy. Tarred nets .become gummy and unmanageable, and when not in the water they harden and are often so rendered use- 40 less. Furthermore, a rotting action is set up from the tar itself, so that its value is somewhat questionable. Coppir salts, on the other hand, although of great nefit in discouraging the marine accumulations are soluble in sea water and soon lose their virtue. To'increase the active life of such salts they have been mixed in a greasy vehicle commonly called copper oleate and used after dilution, or cuttin with gasoline as a bath for coating nets. ut here again a secondary trouble has ensued from the attempted cure. The oily vehicle invariably causes slip ing of the knots resulting in distention o the meshes and escape of fish. This treatment also is laborious and hazardousthe danger of fire from the use of gasoline being always imminent. v p

The principal object of my invention is the inhibition of marine growths.

A further object is the retardation of saline B0 rot and chemical decay.

A further obj ect is the provision of means which obviate the necessity of dip ing or coating of nets withpreservative so utions.

A final object is the provision ofmeans which prevent net distortion and add to its ease of manipulation. 9

Other and more specific objects will be apparent from the following description taken in connection with the accompanying drawi in wherein igure 1 is a view showing a small section of a woven fiber fish net utilizingmy plan of reservation.

igure 2 is an enlarged fragmentary view showing the arrangement in detail of my preservative agent. s

Figure 3 is a cross-sectional view taken along the line 3-3 of Figure 2.

Referring to the drawing, throughout which like reference characters indicate like parts, 4 designates the twine which is woven to form a fish net after the showing of Figure 1. It is normal to arrange the meshes of a fish net approximately in squares as in- 35 dicated, and the various knotsoccurring as at 5 are known as weavers knots. The is a'knot which under ideal conditions will not slip, however, in the process of manufacture it is not possible to tighten the knots securely as they are made, and consequently 1f any'of the greasy or oily preservatives areused it is quite common for them to slip, thus distorting the mesh and making it unsultable for the purpose intended. 9 Fishing nets are normally made of cotton twine, although in some instances linen and hemp are used. In the showing I have represented the type of construction used when m cotton twine is used as the base.

view-showing'the general structure of a sin-' le cord or twine. In the present instance have illustrated what is known to the trade f 5 as a 15 thread cotton cord. This is made up of three .groups of five threads each, whic are twisted together into a single strand somewhat after the fashion of rope making. And each of the three strands are in turn made up of five'threads which'are twisted together to form a unit or cord. Now,.if a larger or smaller sized twine is madeit is normal to vary the number of threads occurring in .each strand but keeping it .at all times three strands to make a single piece of twine.

The most convenient manner in which the poisonous salts of metal may be usedon fish nets is to introduce the metal into the twine and then allow the action of sea water to produce the salts as it decomposes the metal. In this manner salts are produced continuousl throu bout the period the net is in use.

I WlSh itto understood that there are several methods whereby metal may be introduced into the structure of a fishing net. These consist for instance of immersion in a solution of a copper salt followed by chemical precipitation of chloride particles. Perhaps, however, the method indicated in the drawing is the most eflicient method and consists as indicated of weaving a fine metal wire or plurality'of wires into the cord before the mesh is made. v

I have found it convenient in an introduction of metal into a fish net to use a single strand of metal'wi re 12 which is twisted into the strand with threads 6, 7, 8, 9 and 10 which 'go to make up a single strand. In this way when the three strands are twisted together to form the twine the co per wire is well imbedded in the body 0 the twine. In this connection I wish to bring out very clearly that for different types 0 marine growths it is sometimes desirable to ical composition of the wire used. In many instances some of the so called brass Wires contain alloys which are very useful when they are decomposed in the presence of the salt water. v

The gauge size of such wires and the numper .and in makitself to disnism from clinging to its an ace, a definite advantage is at once secured through such retardant property alone. However, though it is only.

slightly soluble. in sea water, and resists chemical attack infsu ch a medium, its ultimate corrosion is. productive of a complex series of poisonousfsalts which are highly devary the chem-' ber of strands emplo ed would of course be structive to marine growths both plant and animal. Sea water contains about cubic centimeters of carbon dioxide per liter, in the orm of carbonates, which in such dilution would be highly ionized. The CO radicle is therefore in a state to enter into ready combination with the cbpperyforming carbonates. These are the greenish salts'which are commonly seen on copper when the metal is exposed to the influence of the atmosphere and moisture. Sea water is the most complex substance known, containing traces at least of the compounds of almost every known element. Consequently many other chemical compounds of copper will be formed, saturating the fibers of the cords and so giving to the net a generally poisonous influence. Since, however, some marine organisms are capable of substituting copper for iron in their systems, and since all of .the salts:

formed through its corrosion are not poisonous, "the use of this metal is not advocated as a panacea for all the ills thatbefall nets from sub-marine a encies; But it should prove to have a i hly retardant effectv against such forces an thus prolong the usefullife of the nets.

A net made from such cord include the valuable chemical lined above but it would also would not only roperties outav'e increased tensile strength due to the presence of the wire, so that it would be more resistant to rupture. Furthermore, the knots would not slip, due to the stifi'ness' of the wire and absence of any oily treatment and thereby. prevent distortion of the meshes, a common source of trouble from the use of greasy coatin? M he foregoing description and the accompanying drawing are believed to clearly disclose apreferred embodiment of my invention but it will be understood that this disclosure is merely illustrative and that such changes in the invention inay be made are fairly within the scope and spirit of the following, claim. a

What I claim is:

A fish net possessing preservative qualitiesand fashioned of twine comprising a plurality of intertwined fiber strands, said strands ing made up of twisted threads, one of said stran said wire being e rosiye action in salt water to form a chemical compound on the net and prevent accumulahavmg a wire contain' copper and intertwined therein, mg at the surface of the twine and subject to cor- 

